244th ACS National Meeting, Philadelphia, PA
http://presentations.acs.org/common/sessions.aspx/Fall2012/SCHB
The following are the abstracts of the terahertz spectroscopy symposium from the 244th ACS National Meeting held in Philadelphia, August 2012. Please use the above link to access the recorded presentations. You’ll have to log in to the ACS website to view the content. Abstracts are listed below (not in any specific order).
Paper-1
INSTITUTIONS
1. Applied Research &Photonics, Harrisburg, PA, 17111, United States
AUTHORS
1. Anis Rahman1 , PhD, Applied Research &Photonics, 470 Friendship Road, Suite 10, Harrisburg, PA, 17111, United States , 717−220−1003, a.rahman@arphotonics.net
2. Aunik K Rahman1 ,
Title: Terahertz time−domain spectrometer calibration and data analysis
Abstract Body: Calibration of a spectrometer involves reproducing known absorption peaks of standard materials to ensure measurement accuracies in a given spectral region. A terahertz spectrometer deploys time−domain measurement where the sample response resulting from the molecular interaction is recorded in time; the spectrum is then obtained by means of converting the time−domain signal by Fourier transform. Here, the absorbance is expected to exhibit established peaks of known standards. In this paper we report calibration of TeraSpectra with polyethylene. While several known peaks of PE have been reproduced, however, TeraSpectra yields additional peaks − owing to its ultra−sensitivity – whose justification may or may not be known. These additional peaks arise because THz radiation is sensitive to resonances due to motions such as translational, rotational, vibrational, torsional, etc. Additional peaks are thus expected and justify the emergence of a new spectrometer where indeed additional information is generated that are not available from its predecessors.
Paper-2
INSTITUTIONS
1. Applied Research &Photonics, Harrisburg, PA, 17111, United States
2. University of Rhode Island, Department of Chemistry, Kingston, RI, 02881, United States
AUTHORS
1. Aunik K Rahman1 , Applied Research &Photonics, 470 Friendship Road, Suite 10, Harrisburg, PA, 17111, United States , 7172201003, info@arphotonics.net
2. Anis Rahman1 , PhD, a.rahman@arphotonics.net
3. Jimmie Oxley2 , PhD, joxley@chm.uri.edu
Title: Explosives traces identification by terahertz spectroscopy
Abstract Body: Detection of explosives from residual traces is the key for preventing unintended use of these materials. We have reported terahertz spectra of common explosives: TNT, PETN and RDX. The temporal signals are found distinctively different in both magnitude and shape, exhibiting unique features for identifying the compounds. In this report we have studied a derivative, DNT, on different backgrounds such as polyethylene, glass, and paper with goal to extract common features in broadband terahertz regime. These results will be present with a comparison with the backgrounds. A protocol will then be worked out to normalize the distance dependence between the target and the detection system. Given the sensitivity of terahertz wavelengths, it seems feasible to accomplish remote detection of explosives with better accuracy. This talk will discuss details with exemplary data.
Paper-3
INSTITUTIONS
1. University of Delaware, Department of Art Conservation, Newark, DE, 19716, United States
2. Villanova University, Department of Chemistry, Villanova, PA, 19085, United States
3. Applied Research &Photonics, Inc., Harrisburg, PA, 17111, United States
AUTHORS
1. Amanda J. Norbutus1 , Winterthur Museum and Country Estates, Rt. 52, c/o Paintings Lab, Winterthur, DE, 19735, United States , 703−944−1371, ajnorbutus@gmail.com
2. Anthony F. Lagalante2 , PhD, 800 Lancaster Ave, Villanova, PA, 19085, United States , 610−519−5409, anthony.lagalante@villanova.edu
3. Richard C. Wolbers1 , Winterthur Museum and Country Estates, Rt. 52, c/o Paintings Lab, Winterthur, Delaware, 19735, United States , 302−888−4818, wolbers@earthlink.net
4. Anis Rahman3 , PhD, 470 Friendship Road, Suite 10, Harrisburg, PA, 17111, United States , 717−220−1003, a.rahman@arphotonics.net
Title: Conservation science and the preservation of outdoor public murals: A multi−analytical investigation via terahertz reflectometry
Abstract Body: Public murals are one of the most visible art forms in the USA, but their extreme visibility is the cause of their greatest vulnerability. The protective coatings play an important role in preservation by providing a barrier between the surface and the environment. Current techniques can analyze only the external surface. A recent development at the Applied Research &Photonics (ARP) enables non−invasive depth profiling of permeating coatings via Terahertz scanning reflectometry. The use of terahertz spectroscopy during this investigation is the first of its kind in public art conservation. Protective coatings on mural paints were artificially aged and monitored at pre−determined intervals. Coatings on Philadelphia murals were also monitored. Targeted studies identified naturally−segregated
mural materials (pigment, additives, and surfactant) and profiled layers to determine bulk and surface chemistry. This will enable an improved fundamental understanding of the composition and aging
characteristics of modern artists' acrylic paints and protective coatings.
Paper-4
1. J. H. Lauterbach & Associates, LLC, Macon, GA, 31210−4708, United States
2. Applied Research &Photonics, Terahertz, Harrisburg, PA, 17111, United States
AUTHORS
1. John H. Lauterbach1 , Ph.D., DABT, Lauterbach &Associates, LLC, 211 Old Club Court, Macon, GA, 31210−4708, United States , 478−474−8818, lauterba@bellsouth.net
2. Anis Rahman2 , PhD, Applied Research &Photonics, Terahertz, 470 Friendship Road, Ste. 10, Harrisburg, PA, 17111, United States , 717−220−1003, a.rahman@arphotonics.net
Title: Use of terahertz spectrometry for analytical chemistry tasks to be required by FDA to meet tobacco products GMP
Abstract Body: Section 906(e) of the Family Smoking Prevention and Tobacco Control Act (P.Law. 111−31, “TCA”) requires the FDA to establish good manufacturing practice (“GMP”) requirements. The FDA is likely to propose the initial GMP requirements in 2012 /2013. The GMP requirements will likely call for analyses verifying that the tobaccos have been manufactured correctly and that the right tobacco blends are being used to manufacture a given cigarette brand−style. Currently such verifications are carried out through batch records and/or offline analyses. Terahertz spectrometry offers the possibility of real−time analyses without the need for complex sample preparation, a feature that is especially attractive to small business tobacco product manufacturers that do not have extensive QA laboratories. An initial evaluation of terahertz spectrometry was conducted to show its ability to distinguish among unprocessed tobacco and manufactured tobaccos taken from finished tobacco products. Some details of the technique will be discussed with exemplary data.
Paper-5
INSTITUTIONS
1. Wright State University, Department of Physics, Dayton, OH, 45435, United States
AUTHORS
1. Benjamin L Moran1 ,
2. Alyssa M Fosnight1 ,
3. Ivan R Medvedev1 , Dr., 3640 Colonel Glenn Highway, Dyaton, OH, 45435, United States , 937−775−2561, ivan.medvedev@wright.edu
Title: Analytical chemical sensing in the submillimeter/terahertz spectral range
Abstract Body: Highly sensitive and selective Terahertz sensor utilized to quantitatively analyze a complex mixture of Volatile Organic Compounds is reported. To best demonstrate analytical capabilities of THz sensors we performed analytical analysis of a certified gas mixture using a novel chemical sensor that couples a commercial preconcentration system (Entech 7100A) to a THz spectrometer. We selected Method TO−14A certified mixture of 39 volatile organic compounds diluted to 1 part per million (ppm) in nitrogen. 26 of the 39 chemicals are suitable for THz spectroscopic detection. Entech 7100A system is marketed as an inlet system for GC−MS instruments with a focus on TO−14 and TO−15 EPA sampling methods. Its efficiency is high for the 39 chemicals in the mixture used for this study and our results confirm this. Here we present the results of this study which serves as basis for our research in environmental sensing and analysis of exhaled human breath.
Paper-6
INSTITUTIONS
1. Rutgers−The State University of New Jersey, Ernest Mario School of Pharmacy and Center for Dermal Research, Piscataway, NJ, 08854, United States
2. Applied Research &Photonics, Terahertz, Harrisburg, PA, 17111, United States
AUTHORS
1. Pei−Chin Tsai1 ,
2. Tannaz Ramezanli1 ,
3. Aunik K Rahman2 ,
4. Anis Rahman2 , PhD, CTO, Applied Research &Photonics, 470 Friendship Road, Ste. 10, Harrisburg, PA, 17111, United States , 717−220−1003, a.rahman@arphotonics.net
5. Bozena B Michniak−Kohn1 , Professor, PhD, Rutgers−The State University of New Jersey, Ernest Mario School of Pharmacy and Center for Dermal Research, 145 Bevier Road, Piscataway, NJ, 08854, United States , 732 445 3589, MICHNIAK@BIOLOGY.RUTGERS.EDU
Title: Kinetics and quantitation of analytes permeation in stratum corneum by terahertz scanning reflectometry
Abstract Body: Direct measurement of quantities governing the permeation of analytes into substrates has been made possible by a recent development at Applied Research &Photonics (ARP). Terahertz scanning reflectometry (TSR) is capable of quantifying the rate of diffusion of an analyte into a substrate and generating the concentration profile of the same along the depth. These capabilities are effectively utilized for investigation of drug candidates for transdermal drug delivery. Measurement of concentration gradient in a non−invasive (non−destructive) fashion is important in several areas such as in the study of penetration behavior of an active ingredient through human skin or other tissues. Two critical factors are: the concentration gradient of ingredient through the stratum corneum and the
kinetics of permeation. Here, the TSR was used for direct measurement of both concentration gradient across the stratum corneum and permeation kinetics of a few important analytes. Details will be discussed with exemplary data.
Paper-7
INSTITUTIONS
1. Applied Research &Photonics, Terahertz, Harrisburg, PA, 17111, United States
2. Columbia University, Chemistry, New York, NY, 10027, United States
AUTHORS
1. Anis Rahman1 , PhD, Applied Research &Photonics, 470 Friendship Road, Suite 10, Harrisburg, PA, 17111, United States , 717−220−1003, a.rahman@arphotonics.net
2. Aunik K Rahman1 ,
3. Nicholas J. Turro2 , Professor, PhD, Columbia University, Department of Chemistry, 3000 Broadway, Mail Code 3119, New York, NY, 10027, United States , 212 854 2175, njt3@columbia.edu
Title: Terahertz spectroscopic analysis of Fullerenes encaging H2 and D2
Abstract Body: The molecular motions of Fullerene C60 and Fullerenes encaging H2 and D2 have been investigated in the low wavenumber region. The encaging Fullerenes offer the opportunity of investigating the spin selectivity of the para and ortho H2 species, so that a stronger nuclear spin polarization may be produced. In the present study we demonstrate that terahertz spectra can clearly distinguish between the pure and encaging Fullerenes. The presence of different absorbance peaks identified by THz spectra suggests that this tool has required sensitivity for detecting the spin isomers of H2 and D2 inside C60. Additionally, the increased number of observed peaks indicates that this method can detect the modes not visible in IR or Raman, yielding unique insight into uncharacterized host−guest interactions. Many of the states identified from THz spectra matches with theoretically predicted states of C60 including a number of degeneracies. These results will be discussed.
Paper-8
INSTITUTIONS
1. National Institute of Standards and Technology, Physics Lab, Radiation & Biomolecular Physics, PML, MD, 20899, United States
AUTHORS
1. Zeeshan Ahmed1 , Dr., PhD, NIST, Radiation and Biomolecular Physics, 100 Bureau Drive, Gaithersburgh, MD, 20899, United States , 301 975 3918, zeeshan.ahmed@nist.gov
2. David F. Plusquellic1 , Dr., PhD, 100 Bureau Drive, Gaithersburgh, MD, United States , 301 975 3896, david.plusquellic@nist.gov
Title: Terahertz Spectroscopy: A new frontier in biophysics and analytical chemistry
Abstract Body: The far−infrared Terahertz (THz) radiation spanning the region 0.1 to 1 mm is exquisitely sensitive to coupled motions of peptides and associated water molecules.1 In particular in the solid state THz active phonon modes of crystalline samples are sensitive to changes in the hydrogen bonding network and other weak interactions as dispersion forces. Sensitivity to weak interactions has opened up new avenues for understanding the role of non−covalent interactions in biophysics and crystal engineering. We have utilized a high resolution THz instrument to systematically study the impact of conformation, hydration and polymorphism on the THz spectra of model peptide systems in a−helix and b−sheet confromations. We have demonstrated that utilizing DFT calculations with high resolution THz data as a benchmark allows us to better define the hydrogen bonding network of the crystal structure and understand the thermochemistry driving intercoversion of various pusedopolymorphs. We are now systematically extending this work to pharmaceutically active small molecules to demonstrate the utility of THz in process chemistry of commercially relevant small molecules.
1. H. Zhang, K. Siegrist, K. O. Douglass, S. K. Gregurick and D. F. Plusquellic, Methods in Nano Cell Biology, Elsevier, Amsterdam, 2008;
2. Zeeshan Ahmed, Shin G. Chou, Karen Siegrist and David Plusquellic, “State−resolved THz spectroscopy and dynamics of crystalline peptide−water systems” Faraday Discuss., 2011, 150 , 1−18
Paper-9
INSTITUTIONS
1. DuPont Corporate Research &Development, Corpoarate Center for Analytical Sciences, Wilmington, DE, 19880, United States
2. Applied Research &Photonics Inc., Terahertz, Harrisburg, PA, 17111, United States
AUTHORS
1. Scott C Brown1 , PhD, DuPont Corporate Research &Development, Corporate Center for Analytical Sciences, Experimental Station E228/214, Rt. 141 &Powder Mill Road, Wilmington, DE, 19880, United States , 302−695−3532, scott.c.brown@usa.dupont.com
2. Aunik K Rahman2 , 470 Friendship Road, Suite 10, Harrisburg, PA, 17111, United States
3. Anis Rahman2 , PhD, 470 Friendship Road, Suite 10, Harrisburg, PA, 17111, United States , 717−220−1003, a.rahman@arphotonics.net
Title: A new approach for monitoring concentrated particle systems with terahertz spectroscopy
Abstract Body: We have applied Terahertz Spectroscopy (THz) for monitoring the size and stability of concentrated nanoparticle suspensions, and have demonstrated that not only is it possible to identify the particle size of a slurry using THz time−domain spectroscopy but also that real−time monitoring of the THz signal attenuation as a simple route for monitoring size transformations within concentrated nanoparticle slurries. The capacity of THz spectroscopy to monitor particle size in dense flows from sub−millimeter to just 20nm in diameter, sets the technique apart from comparable methods. The
potential value of also being able to extract compositional, particle orientation and structural data makes the application of THz in particle metrology highly promising. That said, there is a need to further develop the fundamental interpretation of the THz spectra in order to fully capitalize on the technology for industrial applications. To our knowledge this is the first demonstration of THz for such characterization.
Paper-10
1. Harrisburg University of Science and Technology, Biochemistry, Harrisburg, PA, 17101, United States
2. Applied Research &Photonics, Terahertz, Harrisburg, PA, 17111, United States
3. PennState Hershey College of Medicine, Research Facilities, Hershey, PA, 17033, United States
AUTHORS
1. Nidhi Choksi1 ,
2. Aunik K Rahman2 ,
3. Leena Pattarkine1 , PhD, Harrisburg University of Science and Technology, Biochemistry, 326 Market Street, Harrisburg, PA, 17101, United States , 717.901.5168, LPattarkine@HarrisburgU.edu
4. Anis Rahman2 , PhD, Applied Research &Photonics, Terahertz, 470 Friendship Road, Ste. 10, Harrisburg, PA, 17111, United States , 717−220−1003, a.rahman@arphotonics.net
5. Bruce Stanley3 , PhD, PennState Hershey College of Medicine, 500 University Avenue, Hershey, PA, 17033, United States , (717) 531−5329, bas12@psu.edu
Title: Application of terahertz spectroscopy for DNA diagnostics and detection of single nucleotide polymorphism
Abstract Body: Terahertz spectroscopy is a modern and sensitive technology used for identifying biological molecules for diagnostics applications. Also, terahertz time domain spectroscopy is used for studying the conformational changes in biomolecules. This work describes the terahertz spectra of 21−mer nucleobases for each of Adenine, Thymine, Guanine, and Cytosine, in order to establish their terahertz signatures. It is necessary to understand the absorbance properties of these nucleobases since any DNA molecule is a repetition of these base pair combinations. Additionally, it is important to establish signature peaks for individual nucleotides to study the nature of different hydrogen bondings between them. Therefore, the absorbance spectra for these nucleobases are obtained from their time−domain signal. These spectra are interpreted in terms of the corresponding hydrogen bonding between different nucleobases. This is expected to help generation of a database of the spectral signature of single nucleotide polymorphism (SNP) leading to diagnostics tool and personalized medicine.
